That said, the default is not going to be stopping within 1-2 inches of pedestrians, rather it's going to gradually slow down to deal with pedestrians while trying to maintain forward progress. The point is a self driving car could be more aggressive than most people while staying safe instead of freaking out and just stopping because people are jaywalking.
It's the edge case where a car needs to cross a really high traffic area that's going to be an issue and people can't do 20mph right in front of a high traffic box store entrance etc. Further, going slow for a few hundred feet really does not take that long.
There may still be reasons to prefer robot cars for low-speed environments but the probability of such a vehicle striking and killing a pedestrian is already very low, so that is not relevant to a discussion of a robot car's ability to stop very rapidly at very low speeds.
http://www.nhtsa.gov/people/injury/research/pub/HS809012.htm...
So now you have a long street where tons of people are crossing every 10 meters during the day because it's a quite busy shopping district.
Although cars are driving slow, it must be very hard for autonomous cars because there are people everywhere running in every direction.